Problem description
When the shirt is fully buttoned up, the fabric just below the back of the collar bumps up and comes up over the collar slightly.
Potential solutions
This is a tricky problem that can be caused by a few different factors. We offer a few potential solutions:
- Raising the Shoulder Slope
- Switching to Neck Back 1/2” or 1″
- Increasing the Shoulder (Yoke) Width
Raising the Shoulder Slope
Adjusting the Shoulder Slope to be more raised (eg. from Standard to Raised 0.2″, from Lowered -0.2″ to Standard, etc.) can potentially reduce a bump of fabric behind the back of the collar. If you also exhibit other signs of raised shoulders, such as the pulling lines from the center chest out toward the edge of the shoulders, then this adjustment should be considered first.

Raised Shoulders
Adjusting Neck Posture to ‘Neck Back’
It’s also worth considering adjusting the Neck Posture to remove the bump of fabric behind the back of the collar. Applying the Neck Back posture adjustment will shift the position of the collar backwards relative to the chest and shoulders of the shirt. The severity of the bump will determine whether the Neck Back 1/2″ or Neck Back 1″ setting should be applied. Depending on one’s build, a combination of a more ‘Raised’ Shoulder Slope and a Neck Back posture adjustment may be the solution.
Widening the Shoulder (Yoke) Width
If the Shoulder Slope and Neck Posture appear to agree with the wearer’s build, consider widening the Yoke Width. If the Yoke Width is too narrow, the tension from one’s body pushing against the ends of the shoulder seams can cause the yoke to buckle across the top of the shoulders. This pulling across the shoulders can be the sole cause or a contributing factor to the bump of fabric behind the collar.